<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    table,tr,td{
       border: 1px  solid  orange;
       width: 800px;
       border-collapse: collapse;
    }

    table{
      height: 300px;
    }


    td{
      text-align: center;  /* 表格文本水平居中*/
      vertical-align: center;  /*文本在垂直方向位置*/
    }

    /*隔行变色*/
    tr:nth-child(even){
      background-color: #FFA500;
      color: white;
    }

  </style>
</head>
<body>

<!--
    css操作表格
   border-collapse 属性设置表格的边框是否被折叠成一个单一的边框或隔开
-->

<table>
  <tr>
    <td>11</td>
    <td>12</td>
    <td>13</td>
  </tr>
  <tr>
    <td>21</td>
    <td>22</td>
    <td>23</td>
  </tr>
  <tr>
    <td>31</td>
    <td>32</td>
    <td>33</td>
  </tr>
</table>
</body>
</html>